It must depend upon your subject and university in the UK. As a physicist, I have never known a student to obtain a PhD in less than 3 years. My students have t

It must depend upon your subject and university in the UK. As a physicist, I have never known a student to obtain a PhD in less than 3 years. My students have taken 3.5 years minimum. There's one guy in our department who should get his PhD soon, after 8 years. What you're describing is maybe how they are funded - but not the reality in my experience.